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PatentedNoV. 12, 1889.

Afro/mir.

N. PETERS, PhmUuwgmph-x, wasmngmn. D. C.

I(No Model.)

S. RODMAN, Jr.

3 Sheets-Sheet 2.

INGANDESGENT LAMP SOCKET.-

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Patented Nov. 12, 1889.I

A TTOHNEYS.

(No Model.) 3 Sheets-Sheet 3.

' S. RODMAN, Jr.

INGANDESGENT LAMP SOCKET.

Patented Nov. 12, 1889.

A TTUH/VEY BL PETKNS. Phmmlnhagnplm. waxhingmm D. C

'UNITED STATES PATENT FFICE.

SAMUEL RODMAN, JR., OF THE UNITED STATES ARMY.

INCANDESCENT-LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 414,922, dated November12, 1889.

Application filed February I9, 1889. Serial No. 300,483, (No model.)

The main object of my invention is to produce an electric incandescentlamp wherein the power or intensity of the light may be varied at will;and to the en'd named the inventionconsists of certain novelconstructions, arrangements, and combinations of elements, to behereinafter fully described, and specifically pointed out in the claims.

Reference is to behad to the accompanying drawings, forming a part ofthis speciiication, y

in which similar iiguresand letters of reference indicate correspondingparts in all the views.

Figure lis a side view of my improved electric incandescent lamp, theparts being shown as they appear when all of the filaments are out ofcircuit. Fig. 2 is a central cross-sectional View of the same, the viewbeing taken on the minor axis of the lamp-body, the parts being shownasthey appear when all of the filaments are in circuit. Fig. 3 is asectional View taken on the major axis of the lamp, the position of theparts being the same as in Fig. 2. Fig. 4 is a sectional plan view online :c of Fig. 3. Fig. 5 is a diagram showing the development of thekey-cylinder surface upon a plane surface. Fig. 6 is an inverted planView ofthe fixture-socket. Fig. 7 is a plan view of the lamp-socket.Fig. S is a view of the left-hand end of the key-cylinder. Fig. 9 is acentral sectional eleyation of a modified form of lamp, thisconstruction, however, being the one which I prefer to employ. Fig. lOis an inverted plan view of the modified fixture-socket.

lamp-socket. Fig. 12 is a cross-sectional view on line z z of Fig. i),and Fig. 13 is a diagram illustrating the arrangement of the carbons.

In the drawings, 10 represents a key-box, formed from sections a and b,that are united -by a hinge-joint 11 and held together by hooks or otherfastening devices 12, the box Fig. 11 is a plan view of the being madeof any proper non-conducting material. \Vithin the box 10 there ismounted a cylinder 13, said cylinder being` formed with spiral shouldersc and d and carrying a metallic plate 1t, which extends from theshoulder c to the defining edge of the shoulder d, this plate beingplaced in electric communication with a metallic plug '15, that isiitted into the left-hand end ot' the cylinder 13. The cylinder properand its trunnions are made of non-conducting material, the right-handtrunnion 1G being', it' desired, integral with the cylinder-body, whilethe left-hand trunnion 17 is provided with a projection which fits in arecess formed in the end of the plug 15.

To the top of the box 10 there are secured two binding-posts 1S and 1f),the post 18 being in electric communication with a brush or tongue 20,which bears against the extending portion of the plug 15, and the post1S) is in electric communication with a socket 21, that is secured tothe box 10, said socket being of a proper form and size to receive thelamp-socket.- The socket 21 couldbe secured to the box in anydesiredmanner, but I prefer to establish the connection bymeans ofscrews 22, which pass through lugs or ears 23, that extend upward fromthe socket-body.

To the upper side ot' the bottom 2i of the box IO, I connect a number ofspring-tongues 25, which bear against the peripheral face of thecylinder 13, there being as many of these tongues as there arefilaments-in the lamp, and to the under side of the bottom 24, I securea like number of spring-tongues 26.

In the specific construction illustrated I arrange five 'filaments e, f,g, 7L, and lwithin the globe 30, one end of each of these filamentsbeing electrically connected with contact-plates 31, that are secured tothe upper face of a block 32, said block being held within the upper endof a lamp-socket 33, the wires 3a, by which the connection just referredto is established, passing from the globe through apertures 35, that areformed in the block 32. The other ends of all of the filaments areconnected bya wire 3G,which is supported by two wires that pass throughthe crown of the globe, said two wires in turn being connected to a wire37,

IOO

that is led up through an aperture 38, formed in connection with thesocket Vithin the socket 33, I place a ring 40 of insulating material,which serves as a stop or limit block when the globe is introduced, andat the same time prevents the plaster filling 41 from entering thesocket to an extent such that it might interfere with spring catches 42,mounted within the socket 33 and arranged to enter apertures 44, formedin the socket 21, the spring-catches entering the said apertures whenthe lamp-socket isforced upward into the fixture-socket, and in orderthat the catches may be thrown from engagement with the socket 21, Iprovide each catch with a pushbutton 45, so that by pressing on thebuttons the catches may be thrown inward and the lamp disconnected fromthe fixture-socket.

As before stated, the binding-post 19 is in electric communication withthe socket 21, and as the socket 33 is also in electric communicationwith the socket 21 it follows that the conductor 37, to which one end ofall the filaments is connected, is in electric communication with thepost- 19. To the righthand trunnion 16 ot t-he cylinder 13, I secure athumb-piece 50 and a pointer 51, a dial 52 being arranged in connectionwith the pointer.

'From the construction above described it will be seen that when thecylinder 13 is turned so that all of the tongues 25 will bear againstthat section of the cylinder-face that is between the face ofthe'shoulder d and the edge of the shoulder c all of the filaments willbe out of circuit, and it is when the parts are in this position thatthe pointer will be as shown in Fig. 1; but if the cylinder be turned tothe right the tongue 25 (shown upon the left in Fig. 3, said tonguebeing connected vto the filament i) will pass from the section of thecylinder just referred to and ontothe helical plate 14, thus bringingtmlajngnmginto circuit, the pointer 51 at this time pointing to thedivision 0 upon the dial 52. A further turn of the cylinder will carryit to a position such that the next tongue-that is, the tongue connectedto the filament 7t-will bear against the plate 14, and then the pointerwill point to the division p, and so on until all five of the filamentsare thrown into circuit, the pointer 51 at this time pointing to q.After all the filaments have been thrown into circuit, as justdescribed, any further advance of the cylinder will act to cut out firstthe filament t', then the filament h, and so on until all of thefilaments have been cut out of circuit and the pointer has returned tothe position in which it is shown in Fig. 1.

In the construction illustrated in Figs. 9, 10, 11, 12, and 13 I arrangethe carbons so that they extend radially from a central support 70, eachcarbon being connected to said support and to a wire which is sealednear the edge of the lamp-neck, the globe in this case being round incross-section. By this arrangement I obviate the difficulty due to thewarping of the filaments and more effectually space them.

By means of the arrangement above described it will be seen that with alamp provided with five filaments I am able to secure nine differentdegrees of light; with a lamp embodying six filaments'there would beeleven degrees of light obtainable, the number of degrees beingexpressed bythe formula 21a-l, n representing the number of filamentsemployed.

In practice I prefer to provide the box 10 with a cap or cover 55, butof course this is not essential. To insure a proper action, thefilaments of the lamp should 'all be of practically the same voltage,and although I prefer that the filaments should be of varying power,still all might have the same candlepower.

The switch proper, described herein in connection with a lamp embodyinga number of filaments, might of course be employed in connection with asystem of lamps locatedin a room, dwelling', or district, and it will ofcourse be understood that the indicator arranged in connection with theswitch could be employed to indicate the number of lamps in the circuitand the position of such lamps in any given district, the indicator alsoserving to indicate the candle-power that is being developed, the powerof each filament or lamp being known.

One great advantage arising from the construction above described isthat the life of the lamp is materially increased, inasmuch as the lampmay be used until all of the filaments have lgiven out by using, in alamp having a certain number of filaments of the same candle-power, onefilament at a time until it is burned out, and so on until all areburned out.

Although specific constructions have been described in the foregoingspecification, I desire it to be distinctly understood that anymechanical construction by means of which the broad idea set forth couldbe carried into practice could be used without departing from the spiritof my invention.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, with a series of lightproducingagents, of a switch-cylinder provided with a continuous spiralcontact-plate, spring-tongues which bear against the cylinder, andconnections between the tongues and the light-producing agent,substantially as described.

2. The combination, with a series of lightproducing' agents, of aswitch-cylinder formed with a spiral shoulder, a contact-plate carriedby the cylinder adjacent to said shoulder, spring-tongues which bearagainst the cylinder, and connections between the tongues and thelight-producing agents.

3. The combination, with a series of lightproducing agents, of aswitch-cylinder formed IOO Withspiral shoulders, acontact-plate mountedthe plates, other spring-tongues connected to between said shoulders,spring-tongues which the rst-nanied tongues,a cylinder-key against bearagainst the cylinder, and connections which the second set of tonguesbear, and a between the tongues and the light-producing spiralcontact-plate carried by the key-body,

5 agents, substantially as described. substantially as described.

l 4. In an electric incandescent lamp the i combination, with a seriesof iilaments, of SAMUEL RODMAN JR plates to which one end of each of theiila- Vitiiesses: ments is connected, spring-tongues carried by FRANK G.HARRIS,

1o the fixture-socket and arranged to bear upon LEANDER It?. CARR.

